Immune Deficiency

Much of the time with immune deficiency, a child or adult experiences "too many infections" over a short period of time and is sent for further evaluation. Sometimes, the immune deficiency is diagnosed because someone has an infection that was more severe than what they should have had, or they had an atypical infection that shouldn't have happened if they had a normally working immune system. In some cases, the cause is a genetic defect that has been present from birth.

Typically, patients with primary immunodeficiency disorder experience numerous respiratory or systemic infections that a healthy immune system would fight before symptoms develop. In other patients – adults as well as children and infants – weight loss, chronic gastrointestinal infections and autoimmune diseases, such as immune thrombocytopenia, hemolytic anemia, vitiligo or pernicious anemia, may signal a disorder of the immune system.

The Human Immune System

To understand primary immunodeficiency disorders, it may help to understand how a healthy immune system works. The body is organized by cell units or divisions into an automatically balanced system that keeps us healthy. This system is made up of specialized cells that routinely regulate everyday functions, such as body temperature, blood volume and the ability to fight disease. Any challenge to this delicate balance is usually met by resistance from the system or systems under attack.

In a healthy human being, the body has an inborn defense system against disease called natural immunity. From birth, individual cell groups are poised to fight invaders, such as bacteria entering the body. These "immune cells" are known as white blood cells (WBCs). Among these WBCs are even more specialized cell groups. Each has its own genetically programmed function, much like the rank of soldiers in an army.

When disease-causing bacteria enter the bloodstream from a cut, for example, these invaders are identified as the enemy and the immune system "army" is put on alert. Immediately, pathogen-destroying foot soldiers called macrophages speed up bloodstream activity to root out these disease carriers. This immediate response to invasion in the form of antibody production is known as the primary immune response.

In those with primary immune disorders, however, this natural defense system breaks down. That is why many people with primary immune system disorders experience frequent infections.

Diagnosis

An immune deficiency is diagnosed beginning with a detailed history and exam. Medical records of past infections, past laboratory testing, and past imaging are often reviewed. Blood testing is generally performed to look at the immune system in more depth. Commonly the patient undergoes pre and post specific antibody testing to vaccines to see if they can mount a normal immune response to immunization.

Treatment

Treatment of the immune deficiency depends largely on what the diagnosis is. In some cases continued observation and expectant management or supportive care is used. In some cases, treatment with immunoglobulin is used to supplement the immune system or serve as replacement therapy. In some cases, preventative antibiotics are used. In some cases of immune deficiency the best treatment is stem cell transplant (bone marrow transplant).